At first glance, The Winslow Boy might seem like an improbable choice for David Mamet's sixth directorial effort. Adapted from the play by Terence Rattigan (which has already been filmed once, in 1948 by Anthony Asquith), The Winslow Boy is set in the Edwardian era of pre-World War I England. It seems better suited to the style of Merchant-Ivory than to that of the man who is best-known for writing the four-letter word tirades of Glengarry Glen Ross and American Buffalo. Yet the job Mamet has done here should silence his critics - The Winslow Boy remains true to its source material (although, in his capacity as screenwriter, Mamet has shortened and tightened up the original text). At the same time, it retains an element of Mamet's singular style as a film maker - the characters frequently speak in clipped, staccato sentences. That aspect of the film may be subtle, but it's still there.

Mamet is best known as a playwright. Several of his stage efforts, including the 1984 Pulitzer Prize-winning Glengarry Glenn Ross, Sexual Perversity in Chicago, and American Buffalo have been adapted for the screen. Perhaps oddly, this is only the second time Mamet has filmed a play, and the first time he has worked with someone else's material. Other than Oleanna, all of Mamet's forays behind the camera have been using original scripts (including last year's art house favorite, The Spanish Prisoner) - until The Winslow Boy, which marks a leap of growth in the film maker's reputation.

Loosely based on a true event, The Winslow Boy tells the story of 14-year old Ronnie Winslow (Guy Edwards), a young cadet who was expelled from Britain's Osbourne Naval College in 1908, and his family's arduous struggle to exonerate him of theft and fraud charges. After being found guilty of forging another student's signature in order to steal a five shilling postal order, Ronnie is thrown out of the college and dejectedly returns home. His mother, Grace (Gemma Jones); older sister, Catherine (Rebecca Pidgeon, Mamet's wife); and brother, Dickie (Matthew Pidgeon, Rebecca's brother) all express sympathy and support. His father, Arthur (Nigel Hawthorne), asks one question of his son: Did you steal this postal order? When Ronnie looks his father in the eyes are responds, "No," that's good enough for Arthur to begin a campaign to prove his son's innocence. Arthur's long battle, which becomes a cause celebré, drains his financial resources, saps his strength, and causes everyone in his family to sacrifice. Grace must give up her comfortable lifestyle. Dickie must leave Oxford and go to work. And Catherine loses her fiancé and is forced to contemplate a loveless marriage. Even Sir Robert Morton (Jeremy Northam), the famous lawyer hired by the Winslows to argue their case, turns down a prestigious honor to continue the fight.

The Winslow Boy asks two pointed questions. The first penetrates to the heart of human altruism by examining the point at which the quest for justice turns into an exercise in pride and self-interest. How much of Arthur's fight is really to remove the blight from his son's record and how much is because of his own stubbornness and intransigence? It's clear that Ronnie really doesn't care about the results and everyone else in the family is being hurt, yet Arthur doggedly pushes onward. The second question reiterates a common theme in legal dramas: how does what's right differ from what justice demands? Legally, the Crown cannot be found culpable, yet exonerating Ronnie is the right thing to do. The mantra in this film is not "Let justice be done" but "Let right be done."

The Winslow Boy is a courtroom drama with very few scenes in court. It's a fascinating structure that intellectualizes the material rather than having it appeal on a manipulative, emotional level. Almost the entire trial happens off-screen. We learn about it through conversations in the Winslow house, but we see nothing first hand - not even the verdict. The result is that the focus remains on the thorny ethical issues surrounding the case, not on Ronnie's guilt or innocence, which becomes a relatively small sidebar. In the end, we are given a resolution to the boy's situation, but everything else remains up in the air. Perhaps strangely, that kind of ending satisfies even though there's so little closure. (There is, in fact, great irony in Ronnie's reaction to the court's pronouncement.)

If the movie's approach keeps a gap between the audience and the story, the cool, aloof attitudes of the characters further distance us. Of the principals, only Grace seems completely human. By intent, everyone else is emotionally detached. Catherine and Sir Robert in particular display carefully-constructed facades. Catherine is frequently spoken of as a woman who doesn't show feeling, and, at one point, she remarks of Sir Robert that "I don't think any emotion can stir in that stone heart." There is an element of sexual tension between the two, who are alike in temperament but different in political outlook (she's a suffragette; he's a conservative), but Mamet downplays it, turning it into a minor subplot. A little more emphasis on this aspect of the story might have made for a better balanced picture.

On the acting front, Nigel Hawthorne is wonderful (as always) in the role of Arthur. Hawthorne brings to the fore the central issue of what truly is motivating his character's battle, and it's clear that there's no easy answer. Physically, Hawthorne shows Arthur's deterioration in both subtle and obvious ways. Gemma Jones brings great warmth, humanity, and vulnerability to the part of Grace. Rebecca Pidgeon is completely at home in the reserved confines of Catherine's character, and seems comfortable with Mamet's atypical style of dialogue. Jeremy Northam, who is rapidly becoming a recognizable face (his highest profile role is still the male lead in Miramax's Emma; he soon will be seen as the title character in The Ideal Husband), brings a chilly, debonair style to his interpretation of Sir Robert.

Despite its few failings, The Winslow Boy is a solidly engaging movie. What it lacks in emotional involvement, it makes up for in intelligence and, at times, wit. It's to Mamet's credit that he keeps the tone low-key; in another director's hands, the finale might have turned into the overblown melodrama of a Scent of a Woman. Crafting a period piece of this sort requires an attention to detail that never defeats Mamet. In fact, it is clear that he is always in control of the production. With The Winslow Boy, Mamet illustrates that he can work as capably from someone else's script as he can from his own, and that his talent as a director is not eclipsed by his ability as a writer. Now, I'd like to see what he can do with something by Shakespeare...